High school students rally against gun violence in front of the Capitol in Washington on Wednesday. MUST CREDIT: Washington Post photo by Bonnie Jo Mount

Students calling for an end to gun violence walked out of school Friday, the 19th anniversary of the school shooting in Columbine, Colorado, an event that marked the start of an era of deadly school rampages.

The walkouts Friday were sparked by Lane Murdock, a 16-year-old at Ridgefield High School in Connecticut, who began an online petition calling for the protest following the February shooting in Parkland, Florida, that left 14 students and three staff members dead. Walkouts are planned at more than 2,000 schools nationally, Murdock said.

Several hundred students in the Washington region left their schools Friday morning and staged a vigil outside the White House to honor the Columbine victims and others killed by gun violence.